Hello,
I want to use WCS1800 hall sensor to measure current flow using ADS1115 ADC on my Seeeduino XIAO SAMD21.
My idea is to power the WCS1800 with 5v and use a voltage divider (R1: 10k / R2: 15k) to transform its output from 2.5-5.0v to 1.0-2.0v.
I would appreciate it if you could confirm the correct operation of this design or if anything is missing.
I'm sharing a simple diagram.
Thanks for your advice
Looking at your picture you will get a yes or no answer depending on the current and the pot setting. From you picture you want to use the AOUT from the sensor, I believe that is the analog output. It will measure AC and DC, AC will be a bit tricky as it will swing both + and -. The output may be offset to compensate for this.
The ADS1115 is the wrong type of A/D for the WCS1800.
The WCS is ratiometric, while the ADS is absolute.
This means that the sensor output not only depends on current, but also on sensor supply variations. The 5volt supply of the WCS must be insanely stable to match the 15-bit resolution of the ADS. A band-aid is to alo measure the instantanious supply voltage with a second input of the ADS and use that as a correction factor.
What are you measuring (voltage and current.
For mains power a current transformer and direct measurement with the SAMD21 could be better. For low voltage DC one of the INA sensors (INA226?) could be a better option.
Leo..
Hello everyone, and thank you for your advice.
For my project, I need to drive a DC motor through a relay. If the motor's rated current exceeds 10% for 5 seconds, the relay must open (current protection).
As a solution, I need to implement a DC sensor, but I only need precision in amperes, not milliamps. I want to avoid bolted or soldering connections and that's why I would like to work with the WCS1800 sensor or the QNHCK2-16 sensor.
The microcontroller already has an ADS1115 module that reads a 4-20mA analog sensor. Since I have extra ADS1115 gates, I wanted to use them to read the current sensor (WCS1800).
I look forward to more advice.
I see no need for the ADS1115.
That current sense board also has a threshold detector (the 8-pin chip and trimpot).
Connect the digital output to a digital input of your MCU and set the pot to the required trip current. Code can take care of that 5sec delay.
Measuring the analogue part of the sensor, to see the actual current is optional, but can be done directly with the MCU. No need for that ADS1115 for that either.
The WCS1800 can also take a 3.3volt supply AFAIK, so no resistors needed.
Leo..
Thanks for the information. I'll consider using the digital output to detect overcurrent.
Does that motor turn both directions. Polarity could be important.
Leo..
Upsss, you're right. Some motors have two wires (red and black), and the opening and closing conditions involve polarity changes.
Other motors have three wires (red, black, and white), and in that case, the opening and closing conditions depend on the energization of the black or white wire, with the black wire being the common wire. In this case, I can measure the current in the black wire.
mmm, I should evaluate a common way for both (two- or three-wire) cases to measure the current or the overcurrent device.
I'm implementing a system to operate a gate in an irrigation canal via remote control (cellular signal) and web platform.
Thanks for the advice.
I think the simplest solution is not to measure the motor current but the current feeding the drive system.
This way, I don't have to worry about polarity changes.
I understand that the drive system consumes power, but it's much lower compared to the motor's consumption.
An INA260 (click) could accurately measure up to 15A bi-directional.
And motor voltage and motor power if used high-side (in the (+) line).
Can be directly connected (I2C) and to your 3.3V MCU.
I would also use the SAMD21 to read the 4-20mA signal directly (no ADS needed).
Leo..
